In my U.S. Pat. No. 4,610,704 dated Sep. 9, 1986, there is disclosed a dust collector filter cleaning system including a plurality of venturis mounted in a clean air duct and adapted for pulse firing a jet of compressed air upwardly into the filters to remove particulates therefrom.
The use of conventional venturis of the type shown in the aforementioned patent required that the jet hole be spaced far below the venturi entrance in order to obtain a large quantity of induced air. The required space between the jet hole and venturi entrance resulted in an increase in the height of the collector. In order to reduce the height of the collector while increasing the air mass and thus the effectiveness on cleaning the filters, the venturi of the present invention has been devised.
The venturi of the present invention comprises, essentially, a pair of spaced, vertically extending rectangular plates having divergent opposite end portions integral with a parallel medial portion forming a throat. The lower end portion of the venturi is welded to each side of a compressed air supply pipe and to the interior surface of a clean air duct in which the compressed air pipe is positioned. The throat portion communicates with a plurality of compressed air outlet apertures in the top wall portion of the compressed air supply pipe. At least one axially extending elongated opening is provided in the lower end portion of the face of each plate in proximity to the compressed air outlet apertures, to thereby provide induced air inlets on each side of the venturi together with induced air inlets on each end of the venturi provided by the spaced plates.
By this construction and arrangement, compressed air flowing through the compressed air outlets draws air both laterally through the openings in the plates and longitudinally through the opening at each end of the spaced plates, whereby the induced air mass is increased, thereby increasing the effectiveness of cleaning the filters.